1. Field of the Invention
This application relates generally to an apparatus for protecting workers conducting excavation work and, more specifically, to a protective excavation cage that shields workers within a trench from debris entering the trench when a wall of the trench collapses.
2. Description of Related Art
Excavation work, particularly the excavation of trenches carried out by excavators, has traditionally been dangerous work. Digging machines such as excavators are commonly used to dig large holes in the ground to expose and/or install buried infrastructure such as sewers, water mains and residential lines, gas conduits and other pipelines, buried communication lines such as cables and fiber optic lines. Once the trench is excavated, a worker is often required to enter the hole to perform work along the bottom of the trench. With the worker concentrating on the work being performed at the bottom of the trench, any portion of the trench wall that caves in can possibly cover the worker, thereby trapping the worker in the trench.
To avoid these accidents, numerous laws have been passed requiring the sidewalls of such trenches to be tapered, or laid back outwardly at a specific angle to minimize the chance that the trench wall will collapse, possibly causing harm to the worker in the trench. Wall shoring devices have also been developed to retain the sidewalls of the trench while workers are working therein to prevent such cave-ins. These devices typically have rigid bracing members that bridge the trench to maintain a pre-determined space between the sidewalls of the device, defining a work area between the sidewalls. However, such devices are difficult to assemble, very cumbersome to handle and time consuming to install and remove. U.S. Pat. No. 3,922,866, the contents of which are incorporated herein by reference, shows a prior art worker's cage for excavation work.